Heating Ring With High Thermal Efficiency

Use the Joule effect of electric current to convert electrical energy into heat energy to heat objects. Usually divided into direct resistance heating and indirect resistance heating. The power supply voltage of the former is directly applied to the object to be heated, and when a current flows, the object itself will be heated
Then fever. Objects that can be heated directly by resistance must be conductors, but have a high resistivity. Since the heat is generated from the heated object itself, it belongs to internal heating, and the thermal efficiency is very high. Indirect resistance heating needs to be made of special alloy materials or non-metallic materials to generate heat energy, which is transmitted to the heated object through radiation, convection and conduction. Since the object to be heated and the heating element are divided into two parts, the type of object to be heated is generally not limited, and the operation is simple and convenient.
The material used for the heating element of indirect resistance heating generally requires high resistivity, small temperature coefficient of resistance, small deformation and not easy to embrittle at high temperature. Commonly used are metal materials such as iron-aluminum alloy, nickel-chromium alloy, and non-metallic materials such as silicon carbide and molybdenum disilicide. The maximum working temperature of metal heating elements can reach 1000-1500°C according to the type of material; the maximum working temperature of non-metallic heating elements can reach 1500-1700°C. The latter is easy to install and can be replaced by a hot furnace, but it needs a pressure regulating device when it works, and its life is shorter than that of the alloy heating element. It is generally used in high-temperature furnaces, places where the temperature exceeds the maximum working temperature of the metal material heating element, and some special occasions.